Fungicidal acrylate derivatives

ABSTRACT

Compounds, useful as plant fungicides, having the formula (I): ##STR1## or a stereoisomer thereof, wherein A is CH or N, B is OCH 3  or NHCH 3 , X is CH 2 , CH 2  O, O or S, Y is R 1  --C═C--R 2  or R 1  --CH--CH--R 2  wherein R 1  and R 2  are independently H, halo, hydroxy, alkyl, haloalkyl, alkoxy, haloalkoxy, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or di-alkylaminocarbonyl, alkylcarbonyloxy, optionally substituted aryl, optionally substituted aralkyl or optionally substituted aryloxy or R 1  and R 2  join to form with the carbon atoms to which they are attached an optionally substituted benzene ring, and Z is CH 2 , CHCH 3 , C(CH 3 ) 2  or C═O.

The present invention relates to novel nitrogen-containing heterocyclic compounds, to processes for preparing them, to compositions containing them and to methods of using them to combat fungi, especially fungal infections of plants.

More particularly, the invention relates to fungicidal compounds in which a nitrogen-containing heterocycle is attached through an oxymethylene linking group to a phenyl ring containing an ortho methyl β-methoxyacrylate group or methyl β-methoxyiminoacetate group or an amide derivative thereof.

Fungicidal compounds in which a nitrogen-containing heterocycle is linked through an oxymethylene or thiomethylene group to a phenyl ring containing an ortho methyl β-methoxyacrylate group are described in, for example, EP-A-0278595, EP-A-0350691 and EP-A-0378308. Fungicidal compounds containing a methyl β-methoxyiminoacetate group and amide derivatives are described in, for example, EP-A-0363818 and EP-A-0398692.

According to the present invention there is provided a compound having the general formula (I): ##STR2## or a stereoisomer thereof, wherein A is CH or N, B is OCH₃ or NHCH₃, X is CH₂, CH₂ O, O or S, Y is R¹ --C═C--R² or R¹ --CH--CH--R² wherein R¹ and R² are independently H, halo, hydroxy, alkyl, haloalkyl, alkoxy, haloalkoxy, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyloxy, optionally substituted aryl, optionally substituted aralkyl or optionally substituted aryloxy or R¹ and R² join to form with the carbon atoms to which they are attached an optionally substituted benzene ring, and Z is CH₂, CHCH₃, C(CH₃)₂ or C═O.

Of particular interest are compounds where A is N and B is OCH₃ or NHCH₃ and ore particularly where A is CH and B is OCH₃.

Because the carbon-carbon double bond of the BOC.C═A.OCH₃ group is unsymmetrically substituted, the compounds of the invention may be obtained in the form of mixtures of (E)- and (Z)-geometric isomers. However, these mixtures can be separated into individual isomers, and this invention embraces such isomers and mixtures thereof in all proportions. The (E)-isomers with respect to the BOC.C═A.OCH₃ group are usually the more fungicidally active and form a preferred embodiment of the invention. Similarly, when Y is R¹ --C═C--R² and unsymmetrically substituted, the invention compounds may form further geometric isomers, which can be separated. The invention also includes these isomers.

Further, when Y is R¹ --CH--CH--R² and unsymmetrically substituted or when Z is CHCH₃, the compounds of the invention may exist in the form of mixtures of optical isomers. However, these mixtures can be separated into the component isomers by known methods and this invention embraces such isomers and mixtures thereof in all proportions.

Throughout this description, unless otherwise stated, halo includes fluoro, chloro, bromo and iodo. Alkyl and the alkyl moiety of alkoxy, alkanoyl, etc, can be in the form of straight or branched chains and, unless otherwise stated, suitably contain from 1 to 6, preferably from 1 to 4, carbon atoms. Examples are methyl, ethyl, iso-propyl and tert-butyl, n- or iso-amyl and n-hexyl. Halo(C₁₋₄)alkyl includes halomethyl, eg trifluoromethyl, difluoromethyl, fluoromethyl and trichloromethyl, and halo(C₁ 4)alkoxy includes halomethoxy, eg trifluoromethoxy. Mono- and dialkylamino substituents are suitably mono- and di(C₁₋₄)alkylamino eg. methyl- or dimethylamino, and alkanoylamino is suitably C₁₋₄ alkanoylamino eg formamido and acetylamino. Alkoxycarbonyl is suitably C₁₋₄ alkoxycarbonyl, eg methoxy- and ethoxycarbonyl, and mono- and dialkylaminocarbonyl substituents are suitably mono- and di(C₁₋₄)alkylaminocarbonyl, eg monomethyl and methyl ethylaminocarbonyl. Alkylcarbonyloxy is suitable C₁₋₄ alkylcarbonyloxy, eg acetyloxy. Aryl and the aryl moiety of aralkyl and aryloxy includes naphthyl but will usually be phenyl. Aralkyl is suitably phenyl(C₁₋₄)alkyl, especially benzyl. The aryl group may be optionally substituted with one or more substituents, for example 1 to 3 substituents and usually 1 or 2 substituents, including substituents from the group comprising halo (especially fluoro and chloro), hydroxy, C₁₋₄ alkyl (especially methyl and ethyl), halo(C₁₋₄) alkyl (especially halomethyl, eg trifluoromethyl, difluoromethyl, fluoromethyl and trichloromethyl), C₃₋₆ cycloalkyl (especially cyclopropyl), C₁₋₄ alkoxy (especially methoxy), halo(C₁₋₄)alkoxy (especially halomethoxy, eg trifluoromethoxy), C₁₋₄ alkylthio (especially methylthio), cyano, nitro, amino, mono- or di(C₁₋₄)alkylamino (eg methyl-, ethyl-, dimethyl- and diethylamino), C₁₋₄ alkanoylamino (especially formamido and acetylamino), carboxy, C ₁₋₄ alkoxycarbonyl (especially methoxy- and ethoxycarbonyl), aminocarbonyl, mono- and dialkylaminocarbonyl (eg methyl- and dimethylaminocarbonyl), C₁₋₄ alkylcarbonyloxy (eg acetoxy), phenyl and benzyl, or two adjacent substituents may join together to form a fused benzene ring.

The optionally substituted benzene ring which R¹ and R² may join to form with the carbon atoms to which they are attached, may be substituted with 1 to 4, usually 1 or 2, substituents as described for the optionally substituted aryl group above. A single substituent is suitably in the 6 position of the fused ring system (counting X as 1 and N as 4) or in the 7 position. Di-substituted compounds are suitably substituted in the 5 and 7 or 6 and 8 positions.

In one aspect the invention includes a compound of formula (I) or a stereoisomer thereof, wherein A is CH or N, B is OCH₃ or NHCH₃, X is CH₂, CH₂ O, O or S, Y is CH₂ --CH₂ or R¹ --C═C--R² wherein R¹ is H, alkyl or haloalkyl and R² is H, carboxy, alkoxycarbonyl, aminocarbonyl or mono- or dialkylaminocarbonyl or R¹ and R² join to form, with the carbon atoms to which they are attached, an optionally substituted benzene ring, and Z is CH₂, CHCH₃ or C═O. Where Y is CH₂ --CH₂, typically X is O. Where Y is R¹ --C═C--R² and R¹ and R² do not join to form a benzene ring, X is typically CH₂. In both cases, Z is usually CH₂. Suitably, A is N and B is OCH₃ or NHCH₃. Preferably A is CH and B is OCH₃.

In another aspect the invention includes a compound having the general formula (II): ##STR3## or a stereoisomer thereof, wherein A is CH or N, B is OCH₃ or NHCH₃, X is CH₂, CH₂ O, O or S, R¹ and R² are independently H, halo, hydroxy, alkyl, haloalkyl, cycloalkyl, alkoxy, haloalkoxy, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyloxy, optionally substituted aryl, optionally substituted aralkyl or optionally substituted aryloxy or R¹ and R² join to form, with the carbon atoms to which they are attached, an optionally substituted benzene ring, and Z is CH₂, CHCH₃, C(CH₃)₂ or C═O. Where R¹ and R² do not join to form a benzene ring, X is typically CH₂ and Z is usually CH₂. Examples of such compounds are those where R¹ is H, halo (especially fluoro or chloro) or halo(C₁₋₄)alkyl (especially halomethyl, eg trifluoro- or trichloromethyl, difluoromethyl or monofluoromethyl) and R² is H, carboxy or C₁₋₄ alkoxycarbonyl. Where R¹ and R² join to form a benzene ring X is typically CH₂ or O and Z is typically CH₂ or CHCH₃. In both cases, suitably A is N and B is OCH₃ or NHCH₃, but preferably A is CH and B is OCH₃.

In yet another aspect the invention includes a compound having the general formula (II) or a stereoisomer thereof, wherein A is CH or N, B is OCH₃ or NHCH₃, X is CH₂, O or S, R¹ is H, alkyl or haloalkyl, R² is H, carboxy, alkoxycarbonyl, aminocarbonyl or mono- or dialkylaminocarbonyl, and Z is CH₂, CHCH₃ or C═O. Typically X is CH₂ and Z is usually CH₂. Suitably, A is N and B is OCH₃ or NHCH₃. Preferably A is CH and B is OCH₃.

In yet another aspect the invention includes a compound having the general formula (III): ##STR4## or a stereoisomer thereof, wherein A is CH or N, B is OCH₃ or NHCH₃, X is CH₂, CH₂ O, O or S, Z is CH₂, CHCH₃, C(CH₃)₂ or C═O, D is halo, hydroxy, alkyl, haloalkyl, cycloalkyl, alkoxy, haloalkyl, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or dialkylaminocarbonyl or alkylcarbonyloxy, and m is 0 or an integer of from 1 to 4, with D representing the same or different substituents when m is 2, 3 or 4, or D forms a fused benzene ring with two adjacent carbon atoms of the phenyl ring to which it is attached. Typically m is 0, 1 or 2. Preferably X is CH₂ or O and Z is CH₂ or CHCH₃. Suitably A is N and B is OCH₃ or NHCH₃. Preferably A is CH and B is OCH₃.

In yet another aspect the invention includes a compound having the general formula (IV): ##STR5## or a stereoisomer thereof, wherein A is CH or N, B is OCH₃ or NHCH₃, R¹ and R² are independently H, halo, hydroxy, alkyl, haloalkyl, cycloalkyl, alkoxy, haloalkoxy, alkylthio, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or dialkylaminocarbonyl or alkylcarbonyloxy, or R¹ and R² form with adjacent carbon atoms to which they are attached a fused benzene ring, and R³ is H or CH₃. Suitably, A is N and B is OCH₃ or NHCH₃. Preferably A is CH and B is OCH₃.

In still yet another aspect the invention includes a compound having the general formula (IV) or a stereoisomer thereof, wherein A is CH or N and B is OCH₃ or A is N and B is NHCH₃, R¹ is H, 6-halo (especially 6-fluoro or 6-chloro), 6-C₁₋₄ alkyl (especially methyl or ethyl), 6-halomethyl (eg 6-trichloromethyl, 6-difluoromethyl, 6-monofluoromethyl and especially 6-trifluoromethyl), or 6-nitro, and R² is H or 8-halo (especially 8-fluoro or 8-chloro), 8-C₁₋₄ alkyl (especially methyl or ethyl) or 8-trifluoromethyl, or R¹ is H or 5-halo (especially 5-fluoro or 5-chloro) and R² is 7-halo (especially 7-fluoro or 7-chloro) or 7-C₁₋₄ alkoxy (especially 7-methoxy). Suitably, A is N and B is OCH₃ or NHCH₃. Preferably A is CH and B is OCH₃.

The present invention is illustrated by compounds of the general formulae (V) and (VI) in Tables 1 to 4. Throughout the Tables the W group has the (E)-configuration.

In the compounds of Table 1, W is CH₃ O.CH═C.CO₂ CH₃.

                                      TABLE 1                                      __________________________________________________________________________      ##STR6##                                                                       ##STR7##                                                                      Compound                                                                       No    Structure                                                                           X   Y      Z     D.sub.m                                            __________________________________________________________________________      1    (V)  O   --     CH.sub.2                                                                             6-CF.sub.3                                          2    (V)  O   --     CH.sub.2                                                                             6-Cl                                                3    (V)  O   --     CHCH.sub.3                                                                           6-Cl                                                4    (V)  O   --     CH.sub.2                                                                             7-F                                                 5    (V)  O   --     CH.sub.2                                                                             5,7-di-F                                            6    (V)  S   --     CH.sub.2                                                                             m = 0                                               7    (V)  O   --     CH.sub.2                                                                             6-CH.sub.3                                          8    (V)  O   --     CH.sub.2                                                                             7-CH.sub.3                                          9    (V)  CH.sub.2 O                                                                         --     CH.sub.2                                                                             m = 0                                              10    (V)  O   --     CH.sub.2                                                                             m = 0                                              11    (V)  O   --     CH.sub.2                                                                             7-OCH.sub.3                                        12    (V)  O   --     CH.sub.2                                                                             8-Cl                                               13    (V)  O   --     CH.sub.2                                                                             5-CH.sub.3                                         14    (VI) O   CH.sub.2 CH.sub.2                                                                     CH.sub.2                                                                             --                                                 15    (V)  CH.sub.2                                                                           --     CH.sub.2                                                                             7-Cl                                               16    (V)  O   --     CO    6-Cl                                               17    (V)  O   --     CH.sub.2                                                                             6-CF.sub.3, 8-Cl                                   18    (V)  O   --     CHCH.sub.3                                                                           6-CF.sub.3                                         19    (V)  O   --     CH.sub.2                                                                             6,7-di-Cl                                          20    (V)  O   --     CH.sub.2                                                                             6-NO.sub.2                                         21    (VI) CH.sub.2                                                                           C(CF.sub.3)CH                                                                         CH.sub.2                                                                             --                                                 22    (V)  O   --     CH.sub.2                                                                             5-CF.sub.3                                         23    (V)  O   --     CH.sub.2                                                                             7-CF.sub.3                                         24    (V)  O   --     CH.sub.2                                                                             8-CF.sub.3                                         25    (V)  O   --     CH.sub.2                                                                             5-Cl                                               26    (V)  O   --     CH.sub.2                                                                             5-F                                                27    (V)  O   --     CH.sub.2                                                                             6-F                                                28    (V)  O   --     CH.sub.2                                                                             8-F                                                29    (V)  O   --     CH.sub.2                                                                             5-OCF.sub.3                                        30    (V)  O   --     CH.sub.2                                                                             6-OCF.sub.3                                        31    (V)  O   --     CH.sub.2                                                                             7-OCF.sub.3                                        32    (V)  O   --     CH.sub.2                                                                             8-OCF.sub.3                                        33    (V)  O   --     CH.sub.2                                                                             5-OCHF.sub.2                                       34    (V)  O   --     CH.sub.2                                                                             6-OCHF.sub.2                                       35    (V)  O   --     CH.sub.2                                                                             7-OCHF.sub.2                                       36    (V)  O   --     CH.sub.2                                                                             8-OCHF.sub.2                                       37    (V)  O   --     CH.sub.2                                                                             6,7-di-F                                           38    (V)  O   --     CH.sub.2                                                                             7,8-di-F                                           39    (V)  O   --     CH.sub.2                                                                             5-Br                                               40    (V)  O   --     CH.sub.2                                                                             6-Br                                               41    (V)  O   --     CH.sub.2                                                                             7-Br                                               42    (V)  O   --     CH.sub.2                                                                             8-Br                                               43    (V)  O   --     CH.sub.2                                                                             6-Br, 8-F                                          44    (V)  O   --     CH.sub.2                                                                             6-F, 7-Br                                          45    (V)  O   --     CH.sub.2                                                                             6,8-di-Br                                          46    (V)  O   --     CH.sub.2                                                                             6-CH.sub.3, 8-Br                                   47    (V)  O   --     CH.sub.2                                                                             6-Cl, 7-NO.sub.2                                   48    (V)  O   --     CH.sub.2                                                                             5-NO.sub.2                                         49    (V)  O   --     CH.sub.2                                                                             7-NO.sub.2                                         50    (V)  O   --     CH.sub.2                                                                             8-NO.sub.2                                         51    (V)  O   --     CH.sub.2                                                                             6,8-di-Cl                                          52    (V)  O   --     CH.sub.2                                                                             6-Cl, 7-CH.sub.3                                   53    (V)  O   --     CH.sub.2                                                                             5-cyano                                            54    (V)  O   --     CH.sub.2                                                                             6-cyano                                            55    (V)  O   --     CH.sub.2                                                                             7-cyano                                            56    (V)  O   --     CH.sub.2                                                                             8-cyano                                            57    (V)  O   --     CH.sub.2                                                                             8-CH.sub.3                                         58    (V)  O   --     CH.sub.2                                                                             5-OCH.sub.3                                        59    (V)  O   --     CH.sub.2                                                                             6-OCH.sub.3                                        60    (V)  O   --     CH.sub.2                                                                             8-OCH.sub.3                                        61    (V)  O   --     CH.sub.2                                                                             6-CH.sub.3, 8-OCH.sub.3                            62    (V)  O   --     CH.sub.2                                                                             6,8-di-CH.sub.3                                    63    (V)  O   --     CH.sub.2                                                                             5,7-di-CH.sub.3                                    64    (V)  O   --     CH.sub.2                                                                             6,7-di-CH.sub.3                                    65    (V)  O   --     CH.sub.2                                                                             6-phenyl                                           66    (V)  O   --     CH.sub.2                                                                             6-C(CH.sub.3).sub.3                                67    (V)  O   --     CH.sub.2                                                                             6-CH(CH.sub.3).sub.2                               68    (V)  O   --     CH.sub.2                                                                             6-CH.sub.2 -phenyl                                 69    (V)  O   --     CH.sub.2                                                                             6-sec-butyl                                        70    (V)  O   --     CH.sub.2                                                                             6-cyclopropyl                                      71    (V)  O   --     CH.sub.2                                                                             6-COCH.sub.3                                       72    (V)  O   --     CH.sub.2                                                                             5,6-CHCHCHCH                                       73    (V)  O   --     CH.sub.2                                                                             6,7-CHCHCHCH                                       74    (V)  O   --     CH.sub.2                                                                             7,8-CHCHCHCH                                       75    (V)  O   --     CH.sub.2                                                                             6-OCH.sub.3, 7-Br                                  76    (V)  O   --     CH.sub.2                                                                             6-Br, 7-CH.sub.3                                   77    (V)  O   --     CH.sub.2                                                                             6-F, 8-Cl                                          78    (V)  O   --     CH.sub.2                                                                             5,7-di-F                                           79    (V)  O   --     CH.sub.2                                                                             5,6,8-tri-Cl                                       80    (V)  O   --     CH.sub.2                                                                             5,7-di-CH.sub.3, 6-Cl                              81    (VI) CH.sub.2                                                                           C(CF.sub.3)C                                                                          CH.sub.2                                                                             --                                                                CO.sub.2 C.sub.2 H.sub.5                                        82    (V)  CH.sub.2                                                                           --     CH.sub.2                                                                             6-CF.sub.3                                         83    (V)  S   --     CH.sub.2                                                                             6-CF.sub.3                                         84    (V)  O   --     C(CH.sub.3).sub.3                                                                    6-CF.sub.3                                         85    (V)  O   --     CO    6-CF.sub.3                                         __________________________________________________________________________

TABLE 2

Table 2 comprises 85 compounds having the same structural formulae and the same values of X, Y, Z and Dm as the correspondingly numbered compounds in Table 1. But here W is CH₃ O.CH═C.CONHCH₃.

TABLE 3

Table 3 comprises 85 compounds having the same structural formulae and the same values of X, Y, Z and Dm as the correspondingly numbered compound in Table 1. But here W is CH₃ O.N═C.CO₂ CH₃.

TABLE 4

Table 4 comprises 85 compounds having the same structural formulae and the same values X, Y, Z and Dm as the correspondingly numbered compound in Table 1. But here W is CH₃ O.N═C.CONHCH₃.

TABLE 5

Table 5 shows melting points where measurable or selected proton NMR data obtained at 270 MHz for certain compounds described in Tables 1 to 4. Chemical shifts are measured at 20° C. in ppm from tetramethylsilane and deuterochloroform was used as solvent, unless otherwise stated. The following abbreviations are used:

s=singlet

d=doublet

t=triplet

q=quartet

m=multiplet

br=broad

ppm=parts per million

    ______________________________________                                         Compound                                                                               Melting                                                                No      Point    Proton NMR Data (δ)                                     (Table No.)                                                                            °C.                                                                              ppm                                                           ______________________________________                                         1(1)    87-89                                                                  1(3)    Oil      3.88(3H,s); 4.06(3H,s); 4.58(2H,s); 5.29(2H,s);                                6.9-7.6(7H,m).                                                2(1)    Gum      3.70(3H,s); 3.84(3H,s); 4.51(2H,s); 5.27(2H,s);                                6.77-6.81(1H,d); 6.92-6.98(1H,m);                                              7.14-7.16(1H,d); 7.18-7.22(1H,m);                                              7.32-7.38(2H,m); 7.47-7.52(1H,m);                                              7.59(1H,s).                                                   3(1)    Oil      1.42(3H,d); 3.70(3H,s); 3.84(3H,s);                                            4.63(1H,q); 5.23(2H,q); 6.7-7.5(7H,m);                                         7.59(1H,s).                                                   4(1)    66-68                                                                  5(1)    88-90                                                                  6(1)    Gum      3.25(2H,s); 3.70(3H,s); 3.82(3H,s); 5.30(2H,s);                                7.0-7.6(8H,m); 7.60(1H,s).                                    7(1)    99-101                                                                 8(1)    69-71                                                                  9(1)    Gum      3.70(3H,s); 3.83(3H,s); 4.33(2H,s); 4.54(2H,s);                                5.20(2H,s); 7.05-7.21(4H,m); 7.29-                                             7.39(3H,m); 7.51-7.55(1H,m); 7.60(1H,s).                      10(1)   Gum      3.69(3H,s); 3.82(3H,s); 4.52(2H,s); 5.29(2H,s);                                6.84-7.05(3H,m); 7.14-7.21(2H,m);                                              7.32-7.39(2H,m); 7.49-7.53(1H,m);                                              7.59(1H,s).                                                   11(1)   98-100                                                                 12(1)   132-134                                                                13(1)   93-95                                                                  14(1)   114.2-118                                                              15(1)   Gum      2.6(2H,m); 2.93(2H,m); 3.73(3H,s);                                             3.82(3H,s); 4.48(2H,s); 7.0-7.6(7H,m);                                         7.61(1H,s).                                                   16(1)   150-152                                                                17(1)   Oil      3.70(3H,s); 3.85(3H,s); 4.69(2H,s); 5.30(2H,s);                                7.1-7.6(6H,m); 7.61(1H,s).                                    18(1)   Oil      1.45(3H,d); 3.70(3H,s); 3.85(3H,s);                                            4.72(1H,q); 5.37(2H,q); 6.9-7.5(7H,m);                                         7.60( 1H,s).                                                  19(1)   113-115                                                                20(1)   Oil      3.72(3H,s); 3.87(3H,s); 4.65(2H,s); 5.32(2H,s);                                6.9-8.1(7H,m); 7.62(1H,s).                                    21(1)   Oil      2.33(4H,m); 3.68(3H,s); 3.82(3H,s);                                            5.19(2H,brs); 5.98(1H,m); 7.1(4H,m);                                           7.55(1H,s).                                                   ______________________________________                                    

In general, compounds of formula (I) may be prepared by reacting a compound of formula (VII): ##STR8## wherein X, Y and Z are defined above, with a compound of formula (VIII): ##STR9## wherein A and B are defined above and L is a leaving group such as halogen (chlorine, bromine or iodine) or OSO₂ CF₃, with a suitable base such as silver carbonate in a suitable solvent such as toluene.

Compounds of formula (VIII), particularly where L is bromo, are well documented in the literature and can be prepared by the methods described therein, see for example EP-A-0203606 (wherein A is CH and B is OCH₃), EP-A-0363818 (where A is N and B is OCH₃) and EP-A-0398692 (where A is N and B is NHCH₃). The amides (where B is NHCH₃) may readily be prepared from the corresponding acids (where B is OCH₃) by treating the acid with methylamine in a suitable solvent such as methanol.

The compounds of formula (VII) are commercially available or can be prepared by methods described in the chemical literature. Where Y in the compound (I) is R¹ --CH--CH--R², the compound (VII) is, for example, 3-morpholone or a derivative thereof. Where Y in the compound (I) is R¹ --C═C--R², the compound (VII) is, for example, a tetrahydropyridone. Such compounds are readily available in the laboratory or can be prepared by known techniques. Conveniently, the tetrahydropyridones may be prepared by cyclising acrylic anhydride and a compound of the formula H₂ N--C(R¹)═CH.COO.C₂ H₅ where R¹ is as defined above at a temperature of around 100° C. The ethyl 5-carboxy-3,4-tetrahydro-6-substituted (R¹)pyrid-2-one so obtained may be decarboxylated to provide a compound of the formula (VII) where X and Z are both CH₂ and Y is R¹ --CH--CH₂ or derivatised to form compounds (VII) where X and Z are both CH₂ and Y is R¹ --CH--CH--R² wherein R¹ and R² are as described above.

Where Y in the compound (I) is R¹ --C═C--R² and R¹ and R² join to form a benzene ring, the compound (VII) is, for example, a benzoxazinone. Benzoxazinones of formula (VII) are known in the chemical literature (see for example X Huang and C--C Cann, Synthesis 1984, 851). Conveniently, they may be prepared by treating an optionally substituted 2-aminophenol of formula (IX): ##STR10## with an acid chloride of formula (X): ##STR11## wherein R³ is H or methyl and L is a leaving group as defined above, using a suitable base such as sodium bicarbonate and a phase transfer catalyst, such as triethyl benzylammonium chloride, in a suitable solvent such as dichloromethane. Alternatively, they may be prepared by treating a substituted nitrobenzene of formula (XI): ##STR12## wherein R⁴ is C₁₋₄ alkyl and R³ is as defined above, with a suitable metal such as iron powder in an acid such as acetic acid. Substituted nitrobenzenes of formula (XI) may be prepared by treating an optionally substituted ortho-fluoronitrobenzene of formula (XII): ##STR13## with a hydroxy ester of formula (XIII): ##STR14## wherein R³ and R⁴ are as defined above using a suitable base such as sodium hydride in a solvent such as tetrahydrofuran.

Alternatively, the compounds of formula (I) wherein X, Y and Z are as defined above, A is CH and B is OCH₃ can be prepared from a phenylacetate of formula (XIV) or a ketoester of formula (XV) by the steps shown in Scheme 1. Throughout Scheme 1 the terms X, Y and Z are as defined above, R⁵ is hydrogen or a metal such as sodium or potassium and R is an alkyl group. Each transformation is performed at a suitable temperature and usually, though not always, in a suitable solvent. ##STR15##

Thus, a compound of formula (I) can be prepared by treatment of a phenylacetate of formula (XIV) with a base, such as sodium hydride or sodium methoxide, and methyl formate. If a species of formula CH₃ L', wherein L' is a leaving group such as halide (for example chlorine, bromine or iodine), or a CH₃ SO₄ anion, is then added to the reaction mixture, a compound of formula (I) is obtained. If a protic acid is added to the reaction mixture, a compound of formula (XVI), wherein R⁵ is hydrogen, is obtained. Alternatively, the compound of formula (XVI) wherein R⁵ is a metal such as sodium can be isolated from the reaction mixture.

A compound of formula (XVI) wherein R⁵ is a metal can be converted into a compound of formula (I) by treatment with a species CH₃ L', wherein L' is as defined above. A compound of formula (XVI) wherein R⁵ is hydrogen can be converted into a compound of formula (I) by successive treatment with a base, such as potassium carbonate, and a species of general formula CH₃ L'.

Alternatively, a compound of formula (I) can be prepared from an acetal of formula (XVII) by elimination of methanol under either acidic or basic conditions. Examples of reagents or reagent mixtures which can be used for this transformation are lithium di-isopropylamide, potassium hydrogen sulphate (see, for example, T. Yamada, H. Hagiwara and H. Uda, J. Chem. Soc. Chemical Communications, 1980, 838 and references therein, and triethylamine, often in the presence of a Lewis acid such as titanium tetrachloride (see, for example, K. Nsunda and L. Heresi, J. Chem. Soc. Chemical Communications, 1985, 1000).

Acetals of formula (XVII) can be prepared by treatment of a methyl silyl ketene acetal of formula (XVIII) with trimethyl orthoformate in the presence of a Lewis acid such as titanium tetrachloride (see, for example, K. Saigo, M. Osaki and T. Mukaiyama, Chemistry Letters, 1976, 769).

A methyl silyl ketene acetal of formula (XVIII) can be prepared by treating a phenylacetate of formula (XIV) with a base and a trialkylsilyl halide of formula R₃ SiCl or R₃ SiBr, such as trimethylsilyl chloride, or a base, such as triethylamine, and a trialkylsilyl triflate of formula R₃ Si--OSO₂ CF₃ (see, for example, C. Ainsworth, F. Chen and Y. Kuo, J. Organometallic Chemistry, 1972, 46, 59).

It is not always necessary to isolate the intermediates (XVII) and (XVIII). Under appropriate conditions a compound of formula (I) can be prepared from a phenylacetate of formula (XIV) in "one pot" by the successive addition of suitable reagents listed above.

A phenylacetate of formula (XIV) can be prepared from a phenylacetate of formula (XIX). Thus, if a compound of formula (VI) is treated with a suitable base such as silver carbonate and a phenyl acetate of formula (XIX) added, a phenylacetate of formula (XIV) is obtained.

A phenylacetate of formula (XIX) can be prepared by treating an isochromanone of formula (XX) with HL, wherein L is preferably bromine, in methanol. This transformation can also be accomplished in 2 steps if the isochromanone of formula (XX) is treated with HL in a non-alcoholic solvent, and the resulting phenylacetic acid is then esterified using standard procedures (see, for example, I. Matsumoto and J. Yoshizawa, Jpn. Kokai (Tokkyo Koho) 79138536, 27.10.1979, ChemAbs., 1980, 92, 180829h; and G. M. Lim, Y. G. Perron and R. D. Droghini, Res. Discl., 1979, 188, 672, Chem. Abs., 1980, 92, 128526t). Isochromanones of formula (XX) are well known in the chemical literature.

Alternatively, a compound of formula (I) can be prepared by treatment of a ketoester of formula (XV) with a methoxymethylenation reagent such as methoxymethylenetriphenylphosphorane (see, for example, EP-A-0044448).

A ketoester of formula (XV) can be prepared from a ketoester of formula (XXI), by treatment with a compound of formula (VII) as described above. Ketoesters of formula (XXI) are described in EP-A-0331061.

Compounds of formula (I) where X, Y and Z are as defined above, A is N and B is OCH₃ may be prepared from ketoesters of formula (XV) by treatment with methoxylamine (or a salt of methoxylamine). Moreover these same compounds of formula (I) may be prepared by nitrosation of phenylacetates of formula (XIV) using nitrous acid or an ester of nitrous acid, in the presence of a base such as sodium methoxide, (see for example, O. Touster, Organic Reactions, 1953, 7, 327 and S. Kukolja et al, J. Med. Chem., 1985, 28, 896).

Compounds of formula (I) where A is N and B is the group NHCH₃, may be prepared by treating a compound of formula (X) where A is N and B is OCH₃ with methylamine in a suitable solvent such as methanol.

The compounds of formula (I) are active fungicides and may be used to control one or more of the following pathogens: Pyricularia oryzae on rice and wheat and other Pyricularia spp. on other hosts; Puccinia recondita, Puccinia striiformis and other rusts on wheat, Puccinia hordei, Puccinia striiformis and other rusts on barley, and rusts on other hosts e.g. turf, rye, coffee, pears, apples, peanuts, sugar beet, vegetables and ornamental plants; Erysiphe graminis (powdery mildew) on barley, wheat, rye and turf and other powdery mildews on various hosts such as Sphaerotheca macularis on hops, Sphaerotheca fuliginea on cucurbits (e.g. cucumber), Podosphaera leucotricha on apple and Uncinula necator on vines; Cochliobolus spp., Helminthosporium spp., Drechslera spp. (Pyrenophora spp.), Rhynchosporium spp., Septoria spp. (including Mycosphaerella graminicola and Leptosphaeria nodorum), Pseudocercosporella herpotrichoides and Gaeumannomyces graminis on cereals (e.g. wheat, barley, rye), turf and other hosts; Cercospora arachidicola and Cercosporidium personatum on peanuts and other Cercospora species on other hosts, for example, sugar beet, bananas, soya beans and rice; Botrytis cinerea (grey mould) on tomatoes, strawberries, vegetables, vines and other hosts and other Botrytis spp. on other hosts; Alternaria spp. on vegetables (e.g. cucumber), oil-seed rape, apples, tomatoes, cereals (e.g. wheat) and other hosts; Venturia spp. (including Venturia inaequalis (scab)) on apples, pears, stone fruit, tree nuts and other hosts; Cladosporium spp. on a range of hosts including cereals (e.g. wheat); Monilinia spp. on stone fruit, tree nuts and other hosts; Didymella spp. on tomatoes, turf, wheat and other hosts; Phoma spp. on oil-seed rape, turf, rice, potatoes, wheat and other hosts; Aspergillus spp. and Aureobasidium spp. on wheat, lumber and other hosts; Ascochyta spp. on peas, wheat, barley and other hosts; Plasmopara viticola on vines; other downy mildews such as Bremia lactucae on lettuce, Peronospora spp. on soybeans, tobacco, onions and other hosts, Pseudoperonospora humuli on hops and Pseudoperonospora cubensis on cucurbits; Pythium spp. (including Pythium ultimum) on turf and other hosts; Phytophthora infestans on potatoes and tomatoes and other Phytophthora spp. on vegetables, strawberries, avocado, pepper, ornamentals, tobacco, cocoa and other hosts; Thanatephorus cucumeris on rice and turf and other Rhizoctonia species on various hosts such as wheat and barley, vegetables, cotton and turf; Sclerotinia spp. on turf, peanuts, oil-seed rape and other hosts; Sclerotium spp. on turf, peanuts and other hosts; Colletotrichum spp. on a range of hosts including turf, coffee and vegetables; Laetisaria fuciformis on turf; Mycosphaerella spp. on banana, peanut, citrus, pecan, papaya and other hosts; Diaporthe spp. on citrus, soybean, melon, pear, lupin and other hosts; Elsinoe spp. on citrus, vines, olives, pecans, roses and other hosts; Pyrenopeziza spp. on oil-seed rape and other hosts; Oncobasidium theobromae on cocoa causing vascular streak dieback; Fusarium spp., Typhula spp., Microdochium nivale, Ustilago spp., Urocystis spp., Tilletia spp., and Claviceps purpurea on a variety of hosts but particularly wheat, barley, turf and maize; Ramularia spp. on sugar beet and other hosts; post-harvest diseases particularly of fruit (e.g. Pencillium digitatum and P. italicum and Trichoderma viride on oranges, Colletotrichum musae and Gloeosporium musarum on bananas and Botrytis cinerea on grapes); other pathogens on vines, notably Eutypa lata, Guignardia bidwellii, Phellinus igniarus, Phomopsis viticola, Pseudopezicula tracheiphila and Stereum hirsutum; other pathogens on lumber, notably Cephaloascus fragrans, Ceratocystis spp., Ophiostoma piceae, Penicillium spp., Trichoderma pseudokoningii, Trichoderma viride, Trichoderma harzianum, Aspergillus niger, Leptographium lindbergi and Aureobasidium pullulans; and fungal vectors of viral diseases e.g. Polymyxa graminis on cereals as the vector of barley yellow mosaic virus (BYMV).

Further, some of the compounds may be useful as seed dressings against pathogens including Fusarium spp., Septoria spp., Tilletia spp., (e.g. bunt, a seed-borne disease of wheat), Ustilago spp. and Helminthosporium spp. on cereals, Rhizoctonia solani on cotton and Pyricularia oryzae on rice. In particular, some of the compounds show good eradicant activity against Plasmopara viticola and Pythium ultimum.

The compounds may move acropetally/locally in plant tissue. Moreover, the compounds may be volatile enough to be active in the vapour phase against fungi on the plant. The invention therefore provides a method of combating fungi which comprises applying to a plant, to a seed of a plant or to the locus of the plant or seed a fungicidally effective amount of a compound as hereinbefore defined, or a composition containing the same.

The compounds may be used directly for agricultural purposes but are more conveniently formulated into compositions using a carrier or diluent. The invention thus provides fungicidal compositions comprising a compound as hereinbefore defined and an acceptable carrier or diluent therefor. It is preferred that all compositions, both solid and liquid formulations, comprise 0.0001 to 95%, more preferably 1 to 85%, for example 1 to 25% or 25 to 60%, of a compound as hereinbefore defined.

When applied to the foliage of plants, the compounds of the invention are applied at rates of 0.1 g to 10 kg, preferably 1 g to 8 kg, more preferably 10 g to 4 kg, of active ingredient (invention compound) per hectare.

When used as seed dressings, the compounds of the invention are used at rates of 0.0001 g (for example 0.001 g or 0.05 g) to 10 g, preferably 0.005 g to 8 g, more preferably 0.005 g to 4 g, of active ingredient (invention compound) per kilogram of seed.

The compounds can be applied in a number of ways. For example, they can be applied, formulated or unformulated, directly to the foliage of a plant, to seeds or to other medium in which plants are growing or are to be planted, or they can be sprayed on, dusted on or applied as a cream or paste formulation, or they can be applied as a vapour or as slow release granules.

Application can be to any part of the plant including the foliage, stems, branches or roots, or to soil surrounding the roots, or to the seed before it is planted, or to the soil generally, to paddy water or to hydroponic culture systems. The invention compounds may also be injected into plants or sprayed onto vegetation using electrodynamic spraying techniques or other low volume methods, or applied by land or aerial irrigation systems.

The term "plant" as used herein includes seedlings, bushes and trees. Furthermore, the fungicidal method of the invention includes preventative, protectant, prophylactic, systemic and eradicant treatments.

The compounds are preferably used for agricultural and horticultural purposes in the form of a composition. The type of composition used in any instance will depend upon the particular purpose envisaged.

The compositions may be in the form of dustable powders or granules comprising the active ingredient (invention compound) and a solid diluent or carrier, for example, fillers such as kaolin, bentonite, kieselguhr, dolomite, calcium carbonate, talc, powdered magnesia, fuller's earth, gypsum, diatomaceous earth and china clay. Such granules can be preformed granules suitable for application to the soil without further treatment. These granules can be made either by impregnating pellets of filler with the active ingredient or by pelleting a mixture of the active ingredient and powdered filler. Compositions for dressing seed may include an agent (for example, a mineral oil) for assisting the adhesion of the composition to the seed; alternatively the active ingredient can be formulated for seed dressing purposes using an organic solvent (for example, N-methylpyrrolidone, propylene glycol or N,N-dimethylformamide). The compositions may also be in the form of water dispersible powders or water dispersible granules comprising wetting or dispersing agents to facilitate the dispersion in liquids. The powders and granules may also contain fillers and suspending agents.

The compositions may also be in the form of soluble powders or granules, or in the form of solutions in polar solvents.

Soluble powders may be prepared by mixing the active ingredient with a water-soluble salt such as sodium bicarbonate, sodium carbonate, magnesium sulphate or a polysaccharide, and a wetting or dispersing agent to improve water dispersibility/solubility. The mixture may then be ground to a fine powder. Similar compositions may also be granulated to form water-soluble granules. Solutions may be prepared by dissolving the active ingredient in polar solvents such as ketones, alcohols and glycol ethers. These solutions may contain surface active agents to improve water dilution and prevent crystallisation in a spray tank.

Emulsifiable concentrates or emulsions may be prepared by dissolving the active ingredient in an organic solvent optionally containing a wetting or emulsifying agent and then adding the mixture to water which may also contain a wetting or emulsifying agent. Suitable organic solvents are aromatic solvents such as alkylbenzenes and alkylnaphthalenes, ketones such as cyclohexanone and methylcyclohexanone, chlorinated hydrocarbons such as chlorobenzene and trichlorethane, and alcohols such as benzyl alcohol, furfuryl alcohol, butanol and glycol ethers.

Aqueous suspension concentrates of largely insoluble solids may be prepared by ball or bead milling with a dispersing agent with a suspending agent included to stop the solid settling.

Compositions to be used as sprays may be in the form of aerosols wherein the formulation is held in a container under pressure of a propellant, e.g. fluorotrichloromethane or dichlorodifluoromethane.

The invention compounds can be mixed in the dry state with a pyrotechnic mixture to form a composition suitable for generating in enclosed spaces a smoke containing the compounds.

Alternatively, the compounds may be used in micro-encapsulated form. They may also be formulated in biodegradable polymeric formulations to obtain a slow, controlled release of the active substance.

By including suitable additives, for example additives for improving the uptake, distribution, adhesive power and resistance to rain on treated surfaces, the different compositions can be better adapted for various utilities. Other additives may be included to improve the biological efficacy of the various formulations. Such additives can be surface active materials to improve the wetting and retention on surfaces treated with the formulation and also the uptake and mobility of the active material, or additionally can include oil based spray additives, for example, certain mineral oil and natural plant oil (such as soya bean and rape seed oil) additives, or blends of them with other adjuvants.

The invention compounds can be used as mixtures with fertilisers (e.g. nitrogen-, potassium- or phosphorus-containing fertilisers). Compositions comprising only granules of fertiliser incorporating, for example coated with, a compound of formula (I) are preferred. Such granules suitably contain up to 25% by weight of the compound. The invention therefore also provides a fertiliser composition comprising a fertiliser and the compound of general formula (I) or a salt or metal complex thereof.

Water dispersible powders, emulsifiable concentrates and suspension concentrates will normally contain surfactants, e.g. a wetting agent, dispersing agent, emulsifying agent or suspending agent. These agents can be cationic, anionic or non-ionic agents.

Suitable cationic agents are quaternary ammonium compounds, for example, cetyltrimethylammonium bromide. Suitable anionic agents are soaps, salts of aliphatic monoesters of sulphuric acid (for example, sodium lauryl sulphate), and salts of sulphonated aromatic compounds (for example, sodium dodecylbenzenesulphonate, sodium, calcium or ammonium lignosulphonate, butylnaphthalene sulphonate, and a mixture of sodium diisopropyl- and triisopropylnaphthalene sulphonates).

Suitable non-ionic agents are the condensation products of ethylene oxide with fatty alcohols such as oleyl or cetyl alcohol, or with alkyl phenols such as octyl- or nonylphenol and octylcresol. Other non-ionic agents are the partial esters derived from long chain fatty acids and hexitol anhydrides, alkyl glucosides, polysaccharides and the lecithins and the condensation products of the said partial esters with ethylene oxide. Suitable suspending agents are hydrophilic colloids (for example, polyvinylpyrrolidone and sodium carboxymethylcellulose), and swelling clays such as bentonite or attapulgite.

Compositions for use as aqueous dispersions or emulsions are generally supplied in the form of a concentrate containing a high proportion of the active ingredient, the concentrate being diluted with water before use. these concentrates should preferably be able to withstand storage for prolonged periods and after such storage be capable of dilution with water in order to form aqueous preparations which remain homogeneous for a sufficient time to enable them to be applied by conventional spray equipment. The concentrates may conveniently contain up to 95%, suitably 1-85%, for example 1-25% or 25-60%, by weight of the active ingredient. After dilution to form aqueous preparations, such preparations may contain varying amounts of the active ingredient depending upon the intended purpose, but an aqueous preparation containing 0.0001 to 10%, for example 0.005 to 10%, by weight of active ingredient may be used.

The compositions of this invention may contain other compounds having biological activity, e.g. compounds having similar or complementary fungicidal activity or which possess plant growth regulating, herbicidal or insecticidal activity.

By including another fungicide, the resulting composition can have a broader spectrum of activity or a greater level of intrinsic activity than the compound of general formula (I) alone. Further the other fungicide can have a synergistic effect on the fungicidal activity of the compound of general formula (I). Examples of fungicidal compounds which may be included in the composition of the invention are (E)-N-methyl-2-(2-phenoxyphenyl)-2-methoxyiminoacetamide, (E)-N-methyl-2- 2-(2,5-dimethylphenoxymethyl)phenyl!-2-methoxyiminoacetamide, (RS)-1-aminopropylphosphonic acid, (RS)-4-(4-chlorophenyl)-2-phenyl-2-(1H-1,2,4-triazol-1-ylmethyl)butyronitrile, Z)-N-but-2enyloxymethyl-2-chloro-2',6'-diethylacetanilide, 1-(2-cyano-2-methoxyiminoacetyl)-3-ethyl urea, 4-(2,2-difluoro-1,3-benzodioxol-4-yl)pyrrole-3-carbonitrile, 4-bromo-2-cyano-N,N-dimethyl-6-trifluoromethylbenzimidazole-1-sulphonamide, 5-ethyl-5,8-dihydro-8-oxo(1,3)-dioxol-(4,5-g)quinoline-7-carboxylic acid, α- N-(3-chloro-2,6-xylyl)-2-methoxyacetamido!-γ-butyrolactone, N-(2-methoxy-5-pyridyl)-cyclopropane carboxamide, alanycarb, aldimorph, ampropylfos, anilazine, azaconazole, azafenidin, azoxystrobin, benalaxyl, benomyl, biloxazol, binapacryl, bitertanol, blasticidin S, bromuconazole, bupirimate, butenachlor, buthiobate, captafol, captan, carbendazim, carbendazim chlorhydrate, carboxin, carvone, chinomethionate, chlorbenzthiazone, chloroneb, chlorothalonil, chlorozolinate, clozylacon, copper containing compounds such as copper oxychloride, copper oxyquinolate, copper sulphate, copper tallate, and Bordeaux mixture, cycloheximide, cymoxanil, cyproconazole, cyprofuram, debacarb, di-2-pyridyl disulphide 1,1'-dioxide, dichlofluanid, dichlone, diclobutrazol, diclomezine, dicloran, didecyl dimethyl ammonium chloride, diethofencarb, difenoconazole, difenzoquat, diflumetorim, O,O-di-iso-propyl-S-benzyl thiophosphate, dimefluazole, dimetconazole, dimethomorph, dimethirimol, diniconazole, dinocap, dipyrithione, ditalimfos, dithianon, dodemorph, dodine, doguadine, edifenphos, epoxiconazole, etaconazole, ethirimol, ethoxyquin, ethyl(Z)-N-benzyl-N-( methyl(methylthioethylideneamino-oxycarbonyl)amino!thio)-β-alaninate, etridiazole, famoxadone, fenaminosulph, fenapanil, fenarimol, fenbuconazole, fenfuram, fenpiclonil, fenpropidin, fenpropimorph, fentin acetate, fentin hydroxide, ferbam, ferimzone, fluazinam, fludioxonil, flumetover, fluoroimide, fluquinconazole, flusilazole, flutolanil, flutriafol, folpet, fuberidazole, furalaxyl, furametpyr, furconazole-cis, guazatine, hexaconazole, hydroxyisoxazole, hymexazole, ICIA5504, imazalil, imibenconazole, ipconazole, iprobenfos, iprodione, isopropanyl butyl carbamate, isoprothiolane, kasugamycin, kresoxim-methyl, mancozeb, maneb, mefenoxam, mepanipyrim, mepronil, metalaxyl, metconazole, methfuroxam, metiram, metiram-zinc, metsulfovax, myclobutanil, NTN0301, neoasozin, nickel dimethyldithiocarbamate, nitrothal-isopropyl, nuarimol, ofurace, organomercury compounds, oxadixyl, oxasulfuron, oxolinic acid, oxycarboxin, pefurazoate, penconazole, pencycuron, phenazin oxide, phosetyl-Al, phosphorus acids, phthalide, polyoxin D, polyram, probenazole, prochloraz, procymidone, propamocarb, propamocarb hydrochloride, propiconazole, propineb, propionic acid, prothiocarb, pyracarbolid, pyrazophos, pyrifenox, pyrimethanil, pyroquilon, pyroxyfur, pyrrolnitrin, quaternary ammonium compounds, quinconazole, quinomethionate, quinoxyfen, quintozene, rabenazole, sodium pentachiorophenate, spiroxamine, streptomycin, sulphur, tebuconazole, techlofthalam, tecnazene, tetraconazole, thiabendazole, thicyofen, thifluzamide, 2-(thiocyanomethylthio)benzothiazole, thiophanate-methyl, thiram, timibenconazole, tolclofos-methyl, tolylfluanid, triacetate salt of 1,1'-iminodi(octamethylene)diguanidine, triadimefon, triadimenol, triazbutyl, triazoxide, tricyclazole, tridemorph, triforine, triflumizole, triticonazole, validamycin A, vapam, vinclozolin, XRD-563, zineb and ziram. The compounds of general formula (I) can be mixed with soil, peat or other rooting media for the protection of plants against seed-borne, soil-borne or foliar fungal diseases.

The following Examples illustrate the invention. Throughout the Examples, the term `ether` refers to diethyl ether, magnesium sulphate was used to dry solutions except where otherwise indicated, and solutions were concentrated under reduced pressure. All reactions were performed under an atmosphere of nitrogen and solvents were dried before use, where appropriate. Unless otherwise stated, chromatography was performed on a column of silica gel as the stationary phase. The following abbreviations are used throughout:

ppm=parts per million

mp=melting pot

DMSO=dimethyl sulphoxide

DMF=N,N-dimethylformamide

THF=tetrahydrofuran

Abbreviations for NMR data are as indicated in Table 5.

EXAMPLE 1

This Example illustrates the preparation of methyl(E)-2- 2-(6-trifluoromethyl-2H-benzo 1,4!oxazin-3-yloxymethyl)phenyl!-3-methoxypropenoate. (Compound No. 1 of Table 1).

6-Trifluoromethyl-benzo 1,4!oxazin-3-one (1.0 g), (E)-methyl 2- 2-(bromomethyl)phenyl!-3-methoxypropenoate (1.4 g) and silver carbonate (0.7 g) were heated to reflux in toluene (100 ml) for 5 hours. A further portion of silver carbonate (0.7 g) and (E)-methyl 2- 2-(bromomethyl)phenyl!-3-methoxypropenoate (1.4 g) was added and the mixture heated for a further 5 hours. After cooling the mixture was quenched with water and filtered through Hyflo Supercel. The Supercel was washed with ethyl acetate. The combined organic extracts were washed with sodium hydroxide (2M), then with brine, dried, concentrated and chromatographed using ether:hexane 2:3 to give the title compound (0.173 g, 9% yield) as a white solid mp 87°14 89° C.; ¹ H NMR (270 MHz): 3.70(3H,s), 3.84(3H,s), 4.58(2H,s), 5.30(2H,s), 6.8-7.6(7H,m), 7.60(1H,s) ppm.

EXAMPLE 2

This Example illustrates the preparation of methyl(E)-2- 2-(2-methyl-6-trifluoromethyl-2H-benzo 1,4!oxazin-3-yloxymethyl)phenyl!-3-methoxypropenoate. (Compound No. 18 of Table 1).

Butyl lactate (5.3 g) in THF (40 ml) was added to a suspension of sodium hydride (1.04 g) in THF (10 ml) at 10° C. After 1 hour this was added to a solution of 4-fluoro-3-nitobenzotrifluoride in THF (50 ml) at 10° C. After the addition, the reaction was stirred for 1 hour before being quenched with brine and extracted into ethyl acetate. The combined organic extracts were washed with brine, dried, concentrated then washed through a short plug of silica with ethyl acetate and finally concentrated to give butyl 2-(2-nitro-4-trifluoromethylphenoxy)propionate (12.18 g, 100% yield) as a pale yellow oil; ¹ H NMR (270 Mz): 0.91(3H,t), 1.30(2H,m), 1.61(2H,m), 1.75(3H,d), 4.19(2H,m), 4.95(1H,q), 7.04(1H,d), 7.74(1H,dd), 8.12(1H,d) ppm.

A mixture of butyl 2-(2-nitro-4-trifluoromethylphenoxy)propionate (12.0 g) and iron powder (5 g) in acetic acid (100 ml) was heated to reflux for 1.5 hours. After cooling the reaction mixture was quenched with water and the 2-methyl-6-trifluoromethyl-benzo 1,4!oxazin-3-one (4.49 g, 54% yield) as a grey solid was filtered off and dried mp 142°-4° C.; ¹ H NMR (270 Mz): 1.61(3H,d), 4.76(1H,q), 6.7-7.4(2H,m), 8.89(1H,brs) ppm.

The title compound (0.219 g, 3% yield) as a pale yellow oil was prepared using the method given in Example 1 using the 2-methyl-6-trifluoromethyl-benzo 1,4!oxazin-3-one (4.39 g) described.

EXAMPLE 3

This Example illustrates the preparation of methyl(E)-2- 2-(6-chloro-2H-benzo 1,4!oxazin-3-yloxymethyl)phenyl!-3-methoxypropenoate. (Compound No. 2 of Table 1).

Chloroacetyl chloride (2.39 ml) in dichloromethane (25 ml) was added to a mixture of 5-chloro-2-hydroxyaniline (3.59 g), triethyl benzylammonium chloride (5.7 g) and sodium bicarbonate (8.4 g) in dichloromethane (100 ml) at 0°C. After the addition the mixture was heated to reflux for 4 hours, then cooled and concentrated. The residue was treated with water and the resultant solid washed with ether to give 6-chloro-benzo 1,4!oxazin-3-one (4.2 g, 93% yield) as a buff coloured solid; ¹ H NMR (270 Mz): 3.2(1H,brd), 4.42(2H,s), 6.8-7.0(3H,m) ppm.

The title compound (0.98 g, 16% yield) as a pale yellow oil was prepared using the method given in Example 1 using the 6-chloro-benzo 1,4!oxazin-3-one (2.8 g) described.

EXAMPLE 4

This Example illustrates the preparation of methyl(E)-2- 2-(6-trifluoromethyl-3,4-tetrahydropyridin-2-yloxymethyl)phenyl!-3-methoxypropenoate. (Compound No. 21 of Table 1).

A mixture of acrylic anhydride (1.3 g) and ethyl 3-amino4,4,4-trifluoromethyl-crotonate (1.8 g) were heated to 100° C. for 5 hours. On cooling the product crystallised from the reaction mixture and was isolated by trituration with ether to give ethyl 5-carboxy-3,4-tetrahydro-6-trifluoromethyl-pyrid-2-one (1.1 g, 47% yield) as white solid mp 118°-9° C.; ¹ H NMR (270 Mz): 1.4(3H,t), 2.6(2H,t), 2.8(2H,m), 4.25(2H,q), 7.5(1H,brs) ppm.

Ethyl 5-carboxy-3,4-tetrahydro-6-trifluoromethyl-pyrid-2-one (5.5 g) and lithium chloride (1.3 g) was heated in DMSO (25 ml) at 180° C. (bath temperature) for 16 hours. After cooling the reaction mixture was poured into brine and extracted into ethyl acetate. The combined extracts were washed with water, dried and concentrated to give 3,4-tetrahydro-6-trifluoromethyl-pyrid-2-one (2.2 g, 57% yield) as a white solid mp 101°-3° C.; 1H NMR (270 Mz): 2.5(4H,m), 5.75(1H,m), 7.5(1H,brs) ppm.

3,4-tetrahydro-6-trifluoromethyl-pyrid-2-one (1.1 g), (E)-methyl 2- 2-(bromomethyl)phenyl!-3-methoxypropenoate (1.1 g) and silver carbonate (1.0 g) were heated to reflux in toluene (150 ml) for 5 hours. After cooling the mixture was filtered through Hyflo Supercel. The Supercel was washed with ethyl acetate. The combined organic extracts were washed with brine,dried, concentrated and chromatographed using ether:hexane 3:2. This gave the title compound (132 mg) a clear gum; ¹ H NMR given in Table 5.

EXAMPLE 5

This Example illustrates the preparation of methyl(E)-2- 2-( 5,6!-benzo-cyclohept- 1,4!-oxazin-3-yloxymethyl)phenyl!-3-methoxypropenoate. (Compound No. 9 of Table 1).

Chloroacetyl chloride (2.39 ml in 15 ml of chloroform) was added to a solution of 2-aminobenzyl alcohol(3.08 g), triethylbenzylammonium chloride (5.70 g) and sodium bicarbonate (8.4 g) in chloroform (75 ml) at 0° C. After 1 hour the reaction was heated to reflux for 5.5 hours, then cooled and concentrated. The residue was partitioned between water and ethyl acetate, then the organic extracts were washed with water, dried, and concentrated to give 2-amino-(N-2-chloroacetyl)benzyl alcohol (4.0 g, 98% yield) as a brown oil; ¹ H NMR 4.18(2H,s), 4.73(2H,s), 7.09-7.24(2H,m), 7.32-7.39(1H,m), 8.03-8.07(1H,d), 9.65(1H,brs) ppm.

2-Amino-(N-2-chloroacetyl)benzyl alcohol (1.0 g) in DMF (15 ml) was added to a suspension of sodium hydride (0.34 g) in DMF (10 ml). After 4 hours the reaction mixture was poured into water and extracted with ethyl acetate. The combined extracts were washed with brine,dried and concentrated to give a gum which was triturated with petrol to give 5,6!-benzo-cyclohept- 1,4!-oxazin-3-one (0.5 g, 61% yield) as a fawn coloured solid. ¹ H NMR: 4.59(2H,s), 4.73(2H,s), 6.93-6.97 (1H,d), 7.02-7.15(2H,m), 7.24-7.31(1H,m), 8.51(1H,brs) ppm.

The title compound (0.24 g, 10% yield) was prepared by the method in Example 1 as a pale yellow gum using the 5,6!-benzocyclohept- 1,4!-oxazin-3-one (1.02 g) described.

EXAMPLE 6

This Example illustrates the preparation of methyl(E)-2- 2-(morphol-3-ene-3-yloxymethyl)phenyl!-3-methoxypropenoate. (Compound No. 14 of Table 1). 3-Morpholone (0.61 g), (E)-methyl 2- 2-(bromomethyl)phenyl!-3-methoxypropenoate (1.71 g) and silver carbonate (0.83 g) were heated to reflux in toluene for 4 hours. The mixture was filtered through Hyflo Supercel then concentrated and chromatographed using ethyl acetate to give the title compound as a white powder mp 114.2°-8° C.; ¹ H NMR given in Table 5.

EXAMPLE 7

This Example illustrates the preparation of methyl(E)-2- 2-(2H-benzo 1,4!thiazin-3-yloxymethyl)phenyl!-3-methoxypropenoate. (Compound No. 6 of Table 1).

2H-1,4-Benzothiazin-3(4H)-one (E)-methyl 2- 2-(bromomethyl)phenyl!-3-methoxypropenoate (1.7 g) and silver carbonate (1.0 g) were heated to reflux in toluene for 5 hours. The mixture was filtered through Hyflo Supercel then concentrated and chromatographed using ether hexane 1:1 to give a gum. This gum was further chromatographed using dichloromethane acetonitrile 46:1 to give the title compound as a buff coloured gum; ¹ H NMR is given in Table 5.

EXAMPLE 8

This Example illustrates the preparation of methyl(E)-2- 2-(6-trifluoromethyl-2H-benzo 1,4!oxazin-3-yloxymethyl)phenyl!-(O-methyloximino)acetate. (Compound No. 1 of Table 3).

6-Trifluoromethyl-benzo 1,4!oxazin-3-one (1.3 g), (E)-methyl 2- 2-(bromomethyl)phenylglyoxylate O-methyloxime (1.46 g) and silver carbonate (1.0 g) were heated to reflux in toluene (120 ml) for 6 hours. A further portion of silver carbonate (1.0 g) was added and the mixture heated for a further 24 hours. After cooling the mixture was quenched with water and filtered through Hyflo Supercel. The Supercel was washed with ethyl acetate. The combined organic extracts were washed with brine, dried, concentrated and chromatographed using tert-butyl methyl ether:hexane 3:7 to give the title compound (0.65 g, 30% yield) as an oil; ¹ H NMR is given in Table 5.

EXAMPLE 9

The compounds were tested against a variety of foliar fungal diseases of plants. The technique employed was as follows.

The plants were grown in John Innes Potting Compost (No 1 or 2) in 4 cm diameter minipots. The test compounds were formulated either by bead milling with aqueous Dispersol T or as a solution in acetone or acetone/ethanol which was diluted to the required concentration immediately before use. The formulations (100 ppm active ingredient) were sprayed on to the foliage or applied to the roots of the plants in the soil. The sprays were applied to maximum retention and the root drenches to a final concentration equivalent to approximately 40 ppm a.i. in dry soil. Tween 20 was added to give a final concentration of 0.05% when the sprays were applied to cereals.

For most of the tests the compounds were applied to the soil (roots) or to the foliage (by spraying) one or two days before the plant was inoculated with the disease. Exceptions were the tests on Erysiphe graminis and Puccinia recondita in which the plants were inoculated 24 hours and 48 hours, respectively, before treatment. Foliar pathogens were applied by spray as zoosporangial suspensions onto the leaves of test plants. After inoculation, the plants were put into an appropriate environment to allow infection to proceed and then incubated until the disease was ready for assessment. The period between inoculation and assessment varied from four to fourteen days according to the disease and environment.

The disease level present (i.e. leaf area covered by actively sporulating disease) on each of the treated plants was recorded using the following assessment scale:

0=0% disease present

1=0.1-1% disease present

3=1.1-3% disease present

5=3.1-5% disease present

10=5.1-10% disease present

20=10.1-20% disease present

30=20.1-30% disease present

60=30.1-60% disease present

90=60.1-100% disease present

Each assessment was then expressed as a percentage of the level of disease present on the untreated control plants. This calculated value is referred to as a POCO (Percentage of Control) value. An example of a typical calculation is as follows:

Disease level on untreated control=90

Disese level on treated plant=30 ##EQU1##

This calculated POCO value is then rounded to the nearest of the values in the 9-point assessment scale shown above. In this particular example, the POCO value would be rounded to 30. If the calculated POCO falls exactly mid-way between two of the points, it is rounded to the lower of the two values.

The results are shown in Table 6.

                                      TABLE 6                                      __________________________________________________________________________     Compound No                                                                    (Table No)                                                                            ERYSGT                                                                              LEPTNO                                                                              PUCCRT                                                                              PLATIN                                                                              PHYTIN                                                                              VENTIN                                         __________________________________________________________________________     1(1)   0    0    0    0    0    0                                              1(3)   0    3    --   0    0    0                                              2(1)   0    0    0    0    0    0                                              3(1)   0    0    0    0    0    0                                              4(1)   0    0    0    0    0    0                                              5(1)   0    0    0    0    0    0                                              6(1)   0    30   0    5    0    0                                              7(1)   0    0    0    0    0    0                                              8(1)   0    0    0    0    0    0                                              9(1)   0    0    30   0    0    0                                              10(1)  0    0    0    0    0    0                                              11(1)  0    5    0    0    0    0                                              12(1)  0    10   30   0    0    0                                              13(1)  0    30   5    0    1    0                                              14(1)  30   90   90   0    60   0                                              15(1)  90   30   90   0    1    0                                              16(1)  90   90   60   0    90   0                                              17(1)  0    0    0    0    0    0                                              18(1)  0    0    0    0    0    0                                              19(1)  0    0    0    0    0    --                                             20(1)  0    0    0    0    0    0                                              21(1)  0    0    0    0    0    0                                              __________________________________________________________________________      - No result                                                              

Unless stated otherwise, data represent activity following application as a combined foliar spray and root drench treatment at 100 ppm.

Key to Diseases

ERYSGT Erysiphe graminis tritici

LEPTNO Septoria nodorum

PUCCRT Puccinia recondita

PLASVI Plasmopara viticola

PHYTIN Phytophthora infestans lycopersici

VENTIN Venturia inaequalis 

We claim:
 1. A compound having the general formula (I): ##STR16## or a stereoisomer thereof, wherein A is CH or N, B is OCH₃ or NHCH₃, X is CH₂, CH₂ O, O or S, Y is R¹ --C═C--R² or R¹ --CH--CH--R² wherein R¹ and R² are independently H, halo, hydroxy, alkyl, haloalkyl, alkoxy, haloalkoxy, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyloxy, optionally substituted aryl, optionally substituted aralkyl or optionally substituted aryloxy or R¹ and R² join to form with the carbon atoms to which they are attached an optionally substituted benzene ring, and Z is CH₂, CHCH₃, C(CH₃)₂ or C═O.
 2. A compound according to claim 1 in which Y is CH₂ --CH₂ or R¹ --C═C--R² wherein R¹ is H, alkyl or haloalkyl and R² is H, carboxy, alkoxycarbonyl, aminocarbonyl or mono- or dialkylaminocarbonyl or R¹ and R² join to form, with the carbon atoms to which they are attached, an optionally substituted benzene ring, and Z is CH₂, CHCH₃ or C═O.
 3. A compound according to claim 1 having the general formula (II): ##STR17## or a sterioisomer thereof, wherein A is CH or N, B is OCH₃ or NHCH₃, X is CH₂, CH₂ O, O or S, R¹ and R² are independently H, halo, hydroxy, alkyl, haloalkyl, cycloalkyl, alkoxy, haloalkoxy, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or dialkylaminocarbonyl, alkylcarbonyloxy, optionally substituted aryl, optionally substituted aralkyl or optionally substituted aryloxy or R¹ and R² join to form, with the carbon atoms to which they are attached, an optionally substituted benzene ring, and Z is CH₂, CHCH₃, C(CH₃)₂ or C═O.
 4. A compound according to claim 2 wherein X is CH₂, O or S, R¹ is H, alkyl or haloalkyl, R² is H, carboxy, alkoxycarbonyl, aminocarbonyl or mono- or dialkylaminocarbonyl, and Z is CH₂, CHCH₃ or C═O.
 5. A compound according to claim 1 having the general formula (III) ##STR18## or a sterioisomer thereof, where A is CH or N, B is OCH₃ or NHCH₃, X is CH₂, CH₂ O, O or S, Z is CH₂, CHCH₃, C(CH₃)₂ or C═O, D is halo, hydroxy, alkyl, haloalkyl, cycloalkyl, alkoxy, haloalkyl, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or dialkylaminocarbonyl or alkylcarbonyloxy, and m is 0 or an integer of from 1 to 4, with D representing the same or different substituents when m is 2, 3 or 4, or D forms a fused benzene ring with two adjacent carbon atoms of the phenyl ring to which it is attached.
 6. A compound according to claim 1 having the general formula (IV): ##STR19## or a stereoisomer thereof, wherein A is CH or N, B is B is OCH₃ or NHCH₃, R¹ and R² are independently H, halo, hydroxy, alkyl, haloalkyl, cycloalkyl, alkoxy, haloalkoxy, alkylthio, cyano, nitro, amino, mono- or dialkylamino, alkanoylamino, carboxy, alkoxycarbonyl, aminocarbonyl, mono- or dialkylaminocarbonyl or alkylcarbonyloxy, or R¹ and R² form with adjacent carbon atoms to which they are attached a fused benzene ring, and R³ is H or CH₃.
 7. A compound according to claim 6 wherein A is CH or N, B is OCH₃ or A is N and B is NHCH₃, R¹ is H, 6-halo, 6-C₁₋₄ alkyl, 6-halomethyl or 6-nitro, and R² is H or 8-halo, 8-C₁₋₄ alkyl, or 8-trifluoromethyl, or R¹ is H or 5-halo and R² is 7-halo or 7-C₁₋₄ alkoxy.
 8. A process for preparing a compound according to claim 1 which comprises reacting a compound of formula (VII): ##STR20## wherein X, Y and Z have the meanings given in claim 1, with a compound of formula (VIII): ##STR21## wherein A and B have the meanings given in claim 1 and L is a leaving group, in the presence of a base.
 9. A fungicidal composition comprising a fungicidally effective amount of a compound according to claim 1 and a fungicidally acceptable carrier or diluent therefor.
 10. A method of combating fungi which comprises applying to plants, to the seeds of plants or to the locus of the plants or seeds, a compound according to claim
 1. 